int mbfl_filt_conv_utf7_wchar()

in libmbfl/filters/mbfilter_utf7.c [94:242]

• 140 lines of code
• 46 McCabe index (conditional complexity)

int mbfl_filt_conv_utf7_wchar(int c, mbfl_convert_filter *filter)
{
	int s, n;

	n = -1;
	if (filter->status != 0) {		/* Modified Base64 */
		if (c >= 0x41 && c <= 0x5a) {		/* A - Z */
			n = c - 65;
		} else if (c >= 0x61 && c <= 0x7a) {	/* a - z */
			n = c - 71;
		} else if (c >= 0x30 && c <= 0x39) {	/* 0 - 9 */
			n = c + 4;
		} else if (c == 0x2b) {			/* '+' */
			n = 62;
		} else if (c == 0x2f) {			/* '/' */
			n = 63;
		}
		if (n < 0 || n > 63) {
			if (c == 0x2d) {
				if (filter->status == 1) {		/* "+-" -> "+" */
					CK((*filter->output_function)(0x2b, filter->data));
				}
			} else if (c >= 0 && c < 0x80) {	/* ASCII exclude '-' */
				CK((*filter->output_function)(c, filter->data));
			} else {		/* illegal character */
				s = c & MBFL_WCSGROUP_MASK;
				s |= MBFL_WCSGROUP_THROUGH;
				CK((*filter->output_function)(s, filter->data));
			}
			filter->cache = 0;
			filter->status = 0;
			return c;
		}
	}

	switch (filter->status) {
	/* directly encoded characters */
	case 0:
		if (c == 0x2b) {	/* '+'  shift character */
			filter->status = 1;
		} else if (c >= 0 && c < 0x80) {	/* ASCII */
			CK((*filter->output_function)(c, filter->data));
		} else {		/* illegal character */
			s = c & MBFL_WCSGROUP_MASK;
			s |= MBFL_WCSGROUP_THROUGH;
			CK((*filter->output_function)(s, filter->data));
		}
		break;

	/* decode Modified Base64 */
	case 1:
	case 2:
		filter->cache |= n << 10;
		filter->status = 3;
		break;
	case 3:
		filter->cache |= n << 4;
		filter->status = 4;
		break;
	case 4:
		s = ((n >> 2) & 0xf) | (filter->cache & 0xffff);
		n = (n & 0x3) << 14;
		filter->status = 5;
		if (s >= 0xd800 && s < 0xdc00) {
			s = (((s & 0x3ff) << 16) + 0x400000) | n;
			filter->cache = s;
		} else if (s >= 0xdc00 && s < 0xe000) {
			s &= 0x3ff;
			s |= (filter->cache & 0xfff0000) >> 6;
			filter->cache = n;
			if (s >= MBFL_WCSPLANE_SUPMIN && s < MBFL_WCSPLANE_SUPMAX) {
				CK((*filter->output_function)(s, filter->data));
			} else {		/* illegal character */
				s &= MBFL_WCSGROUP_MASK;
				s |= MBFL_WCSGROUP_THROUGH;
				CK((*filter->output_function)(s, filter->data));
			}
		} else {
			filter->cache = n;
			CK((*filter->output_function)(s, filter->data));
		}
		break;

	case 5:
		filter->cache |= n << 8;
		filter->status = 6;
		break;
	case 6:
		filter->cache |= n << 2;
		filter->status = 7;
		break;
	case 7:
		s = ((n >> 4) & 0x3) | (filter->cache & 0xffff);
		n = (n & 0xf) << 12;
		filter->status = 8;
		if (s >= 0xd800 && s < 0xdc00) {
			s = (((s & 0x3ff) << 16) + 0x400000) | n;
			filter->cache = s;
		} else if (s >= 0xdc00 && s < 0xe000) {
			s &= 0x3ff;
			s |= (filter->cache & 0xfff0000) >> 6;
			filter->cache = n;
			if (s >= MBFL_WCSPLANE_SUPMIN && s < MBFL_WCSPLANE_SUPMAX) {
				CK((*filter->output_function)(s, filter->data));
			} else {		/* illegal character */
				s &= MBFL_WCSGROUP_MASK;
				s |= MBFL_WCSGROUP_THROUGH;
				CK((*filter->output_function)(s, filter->data));
			}
		} else {
			filter->cache = n;
			CK((*filter->output_function)(s, filter->data));
		}
		break;

	case 8:
		filter->cache |= n << 6;
		filter->status = 9;
		break;
	case 9:
		s = n | (filter->cache & 0xffff);
		filter->status = 2;
		if (s >= 0xd800 && s < 0xdc00) {
			s = (((s & 0x3ff) << 16) + 0x400000);
			filter->cache = s;
		} else if (s >= 0xdc00 && s < 0xe000) {
			s &= 0x3ff;
			s |= (filter->cache & 0xfff0000) >> 6;
			filter->cache = 0;
			if (s >= MBFL_WCSPLANE_SUPMIN && s < MBFL_WCSPLANE_SUPMAX) {
				CK((*filter->output_function)(s, filter->data));
			} else {		/* illegal character */
				s &= MBFL_WCSGROUP_MASK;
				s |= MBFL_WCSGROUP_THROUGH;
				CK((*filter->output_function)(s, filter->data));
			}
		} else {
			filter->cache = 0;
			CK((*filter->output_function)(s, filter->data));
		}
		break;

	default:
		filter->status = 0;
		break;
	}

	return c;
}